The impact of short term storage on power system operation

Author(s):  
Joseph Devlin ◽  
Kang Li ◽  
Paraic Higgins ◽  
Aoife Foley
2018 ◽  
Vol 234 ◽  
pp. 03004 ◽  
Author(s):  
Paweł Krzaczek ◽  
Arkadiusz Rybak ◽  
Andrzej Bochniak

The aim of the research was to determine the impact of biofuels from waste materials of plant and animal origin on the parameters of the common rail power supply system in the utility engine. The tests included identification of power system operation parameters in the whole load range of the tested engine, taking into account the limit and diagnostic parameters of the injectors operation. Then, for certain parameters, the engine injectors were tested on the test bench: injection pressure in the range of 25-135 MPa, injection time in the range of 200-1600 μs. In the tests, as reference fuel for testing injectors were used diesel fuel and three types of methyl esters of higher fatty acids: vegetable, animal and WCO origin. The measurements for individual fuels were made in the operating temperature range 30-60°C. The tests have shown significant changes in the volume of the fuel injection rates depending on the fuel used. Particularly, visible changes concerned the power system operation parameters for high engine speeds and the maximum working pressure of the common rail system in the engine.


2020 ◽  
Vol 12 (21) ◽  
pp. 9225
Author(s):  
Anis Adiba Zawawi ◽  
Nur Fadilah Ab Aziz ◽  
Mohd Zainal Abidin Ab Kadir ◽  
Halimatun Hashim ◽  
Zmnako Mohammed

Geomagnetic induced current (GIC) occurs as a direct consequence of abnormal space weather which starts from the sun and may flow into a power system network through neutral grounding connections. The flow of GIC through grounded neutral power transformer has been a major concern to researchers since it can potentially affect power system equipment. Most of the previous research was focused on high and mid latitude countries only. However, it has been proven that the GIC is not only limited to high and mid latitudes, but also extends to power systems at lower geographic latitudes. This paper aims to investigate the impacts of GIC on selected 275 kV subpower system networks in Peninsular Malaysia, which is among the low latitude countries. Its impact in terms of magnitude and duration is also assessed together with the use of neutral earthing resistor (NER) as a potential blocking component to reduce the impact of GIC on the Malaysian power system network. Results demonstrated that when GIC exists in the power system, power transformers undergo half-cycle saturation that may lead to a reactive power loss and power system voltage instability. In this case, the power transformer can only withstand a maximum GIC value of 7 A, and beyond this value, if prolonged, may lead to voltage instability. It turned out that GIC magnitude had more impact compared to duration. However, long duration with high magnitude of GIC is the most hazardous to power transformers and could potentially cause major faults in the power system network. As part of mitigation, NER with a value of 315.10 Ω can be used to limit the GIC current flow and thus provide protection to the power system network. Clearly, the issue of GIC undoubtedly affects the reliability, security and sustainability of power system operation, especially networks with highly critical load and capacity and, therefore, thorough studies are required to assess and mitigate this issue.


Author(s):  
Weixuan Lin ◽  
Rui Xia ◽  
Dawei He ◽  
Ronald G. Harley ◽  
Thomas G. Habetler

Energies ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3583 ◽  
Author(s):  
Aliyu Hassan ◽  
Yskandar Hamam ◽  
Josiah L. Munda

In power system operations, unforeseen energy imbalances commonly occur, resulting in unexpected constraints on the system. This leads to a disturbance in normal operation. In systems with integration of large intermittent wind power resources, additional complications are imposed on the system, especially under heavy winds that require immediate measures to minimize possible impact of abrupt wind power fallout. Effective power system fortifications have to be put in place to address the challenges. Wind varies more on the sub-hourly time scales; therefore, sub-hourly dispatch is bound to address more of these issues than commonly used hourly methods. Hybrid power system operation with wind necessitates the use of fast start-up generation and storage to improve quality of power. In this work, the impact of intermittent wind power curtailment on power system operation is addressed to prevent system instability. A modified wind turbine power curve is used to restrict the onset of the normal cut-off point, thereby allowing sufficient time for effective power switchover with pumped hydro generation. This improves the voltage stability of the power system during curtailment. Singular value decomposition matrix of the power system network is employed to evaluate the performance of the proposed method.


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